1. Field of the Invention
This invention relates to lighting appliances which are intended to be employed in particular for taking photographs, shooting films or the like.
2. Description of the Prior Art
For applications of this type, the light sources usually employed (such as small flash tubes, halogen lamps, metal vapor lamps or gas-discharge lamps) are subject to disadvantages if they are used as they stand for lighting a subject. The lighting thus obtained is in fact too harsh and not only casts shadows which are too sharp but also produces reflections which are too bright. In order to obtain soft and more satisfactory lighting, it would prove necessary to increase the dimensions of the light source to a considerable extent. This would indeed have the effect of producing shadows which are more diffuse and less sharply contrasted. Furthermore, the subject would be illuminated under better conditions since he or she would not be hindered by dazzling light. However, in order to achieve a really adequate result, the increase in dimensions of the light source would in that case have to be considerable.
In order to solve this problem, different known types of lighting appliances have already been proposed for the use of a small-size light source for the production of diffused lighting of larger size and oriented towards the subject to be illuminated. With this objective, appliances of this type are provided with diffusion screens on their outer face.
It has thus been proposed to provide lighting appliances with curved reflectors made of aluminum or molded plastic. However, these appliances are particularly costly and the results obtained are not entirely satisfactory.
A folding reflector has also been proposed in the form of an umbrella with a light source placed at the center. Devices of this type do have the advantage of low cost but are still attended by a certain number of disadvantages from a practical standpoint. From a photographic point of view, they also have the disadvantage of producing certain troublesome reflections (circular reflection with a dark spot at the center corresponding to the location of the light source and lines corresponding to the stiffening members of the umbrella frame).
For the application under consideration, another existing type of lighting appliance consists of a rigid box having the shape of a pyramid or the like and having internal reflecting walls placed around a light source with a diffusion screen placed in front. Current devices of this type, however, are relatively heavy and costly to produce. Furthermore, the lighting provided by these devices falls short of the required standard.